List

#include <fstream>
#include <bitset>
using namespace std;

ifstream in("list.in");
ofstream out("list.out");

struct Nod
{
    int a,b;
    Nod* next;
};
typedef struct Nod * Lista;

void ADD(Lista &Prim, Lista Ultim, int x, int y)
{
    Lista nod=(Nod *)malloc(sizeof(Nod *));
    nod->a=x;
    nod->b=y;
    nod->next=NULL;
    if(Ultim==NULL)
    {
        nod->next=Prim;
        Prim=nod;
    }
    else
    {
        nod->next=Ultim->next;
        Ultim->next=nod;
    }
}

int n;

int main()
{
    Lista Prim=NULL, Ultim=NULL;
    in>>n;
    for(;n;n--)
    {
        int x,y;
        in>>x>>y;
        if(Ultim==NULL)
        {
            ADD(Prim,NULL,x,y);
            Ultim=Prim;
        }
        else
        {
            ADD(Prim,Ultim,x,y);
            Ultim=Ultim->next;
        }
    }
     Lista slow=NULL,fast=Prim;
    for(Lista p=Prim; p; p=p->next)
    {
        if(p->a%2==0 && p->b%2)
        {
            int w=2*(p->a+p->b);
            ADD(Prim,p,w,w-p->b);
            p=p->next;
            slow=fast;
        fast=fast->next;
        }
        else if(p->a%2 && p->b%2==0)
        {

            int w=2*(p->a+p->b);
            ADD(Prim,slow,w-p->a,w);
        }
         else if(p->a%2==0 && p->b%2==0)
        {
            int w=(p->a+p->b)/2;
            ADD(Prim,p,w,w+p->b);
            p=p->next;
             slow=fast;
        fast=fast->next;
        }
        else
        {

            int w=(p->a+p->b)/2;
            ADD(Prim,slow,w+p->a,w);
        }
         slow=fast;
        fast=fast->next;
    }

    for(Lista q=Prim; q; q=q->next)
    out<<q->a<<" "<<q->b<<"\n";

    return 0;
}